J. A. Kiernan, Quart. J. of Exp. Physiol., (1977) 62, 151-161, states that capsaicin, N-(3-methoxy-4-hydroxybenzyl)-8-methyl-6-nonenamide, is known to confer resistance to certain chemical irritants.
Jancso, et al., Br. J. Pharmac. Chemother. (1967), 31, 138-151, states that by repeated administration of capsaicin, ocular and/or cutaneous pain receptors can be desensitized to chemical, but not other, stimuli.
Arvier, et al., Br. J. Pharm. (1977), 59, 61-68, indicate that capsaicin reduces or blocks the edema formation associated with certain types of inflammation.